Need advice on what is the best approach to get the auto incremented id to be the same on multiple forms.
Basically I am using VB .Net with SQL Server as the backend. I wrote a few stored procedures to insert data and then I am calling the stored procedures on the front end. I have 3 forms and once the first form is submitted it generates an autoID and then takes the user to 2nd form.
In the second form I have a separate insert stored procedure is there a way to grab the id that the first form generated and for it to be consistent. Or should I store it in a variable after they submit the form and then call it in the second form.
I read about the ##Identity but that only grabs the id within that session since I am submitting the first forms data then going to the second wouldn't that be a different session.
Thanks
Your stored proc could return the identity value (use the output clause or scope_identity() to get it) as an output variable that you would store as a variable in your application, then it would be available to use. You would want to make sure to null out the varaible when the person moves to a differnt record and after allthe associated formas have inserted records, so that you don;t inadvertently use it at some other time.
You do not want to ever use ##identity for this as it is unreliable and can create massive data integrity issues as it will give you the wrong value if someone adds a trigger that inserts to another table with an identity.
The fact that this is causing you problems might be an indicator that this isn't the best way to do it. Perhaps instead, use a function on the DB to return the ID, and then set it in your .net code?
If you have an auto incremented ID, then it should only increment when a record is created. Are your three forms creating three records? Is that what you want? If so, then an auto ID is definitely not the right way to go.
I think maybe your over thinking this?
I read about the ##Identity but that only grabs the id within that session since I am submitting the first forms data then going to the second wouldn't that be a different session.
Don't you want the key that was generated by the entries made on the first form?
In the second form I have a separate insert stored procedure is there a way to grab the id that the first form generated and for it to be consistent. Or should I store it in a variable after they submit the form and then call it in the second form.
Related
In my application I work with Sqlite. In one of the tables inside database I've implemented a trigger (basically, after an insert event on the table TAB, it has to update a column named codecolumn which depends on the ID PK field)
In my code I create and object from a PeeweeModel previously setted
objfromModel = Model(params....)
After the execution of line:
objfromModel.save()
We hoped to get appart from the _id field generated -in fact objfromModel.id is retrieved from DB-, but also the codecolumn new field generated by the trigger execution on insert event. But objfromModel.codecolumn is None
Question: is there a trick to make on Peewee in order to recover this new field generated in database by trigger.
Unfortunately SQLite does not support the concept of INSERT ... RETURNING. What you could do is a couple of things:
A. After creation simply re-fetch the codecolumn. e.g. self.codecolumn = MyModel.select(MyModel.codecolumn).where(MyModel.id == self.id).scalar(convert=True) (the use of "scalar" says return just one value, the "convert=True" says convert the underyling database type to a Python type. This is really only necessary if the database type is a date or datetime
B. Create a post-insert trigger that calls a user-defined function. Register a handler for the user-defined function on your database instance, and have your callback receive the new codecolumn value and set it as a database attribute in the callback. Hopefully this makes sense?
C. Move the codecolumn trigger out of SQL and into Python, making it easier to know ahead-of-time what its value will be. This depends obviously on what that column contains.
Hope these ideas help.
I am using formit in modx to create a form for the user to fill in. I then created a snippet to store the data from the form so that I can write it into my database. I followed closely to Bob's guide: http://bobsguides.com/custom-db-tables.html and I have searched online where similar approach has been made. However, my problem is that only one entry is stored each time. In other words, my table has only one record despite the fact that more than one user has filled the form and the record does not get overwritten. For new record to be stored, the current record must first be deleted. I am not sure what might be causing this problem. Makes no sense? Any suggestions would be much appreciated.
I'm currently creating my first real life project in Pervasive. The task is to map a certain XML structure containing orders (as in shops and products) to 3 tables I created myself. These tables rest inside a MS-SQL-Server instance.
All of the tables have a unique key called "id", an automatically incremented column. I've dropped this column from all mappings so that Pervasive will not try to fill it itself.
For certain calculations, for a split key in one of the tables and for references to the created records in other tables, I will need the id that the database has just created. For that, I have googled the answer. I can use "select ##identity;" as a statement, and this returns the id that has most recently been created for the current connection. This means that in Pervasive, I will have to execute this statement using the already existing target connection object.
But how to do that? I am quite sure that I will need a JDImport or DJExport object, but how to get one associated with the current connection that Pervasive inserts the records by?
Or is there any other way to handle this auto increment when I need to reference the id in other tables?
Not sure how things work in Pervasive, but you may run into issues with ##identity,. Scope_identity() would probably be safer but may still not work in Pervasive.
Hopefully your tables have a natural key in addition to the generated id, in which case you can select your id based on the natural key. This will avoid any issues you may have with disparate sessions and scope.
If there is anyone looking this post up and wonders about the answer, it's "You can't". Pervasive does not allow access to their very own connection object, the one they use to query the database. Without access to it, you cannot guaranteed fetch the right id. The solution for us was this: We used a stored procedure which we called in the Before-Transformation event that created the header record and returned the id and an optional error message as a table. We executed it and it returns the id we then save and use throughout our mapping.
Is it possible to force a field to always be a certain value?
We have a website in production that writes a value entered by the user into a string field. Now, our requirements have changed and we no longer actually want to save this value. For technical reasons, we don't want to do a new publish just for this if we don't have to.
What would be ideal is to ALTER the table in such a way that the field will always be NULL and that existing INSERTS and UPDATES into the field will work as normal but SQL Server will NULL the field regardless.
This is a temporary thing. We will eventually change the code to not write this value.
Just looking for a quick way to NULL the field without changing code, republishing etc...
Is this possible? Is writing a trigger the only solution?
Thanks!
You could make an INSERT and UPDATE after trigger that will NULL the field each time it is updated / inserted into.
This is the quickest and easiest solution.
I am getting the following error in an MS Access ADP when trying to add a record on a form linked to a MS SQL Server 2000 table:
Run-time error '31004':
The value of an (AutoNumber) field
cannot be retrived prior to being
saved.
Please save the record that contains
the (AutoNumber) field prior to
performing this action.
note: retrieved is actually spelled wrong in the error.
Does anyone know what this means?
I've done a web search and was only able to find the answer at a certain site that only experts have access to.
First of all, if you are going to look at experts-exchange - do it in FireFox, you'll see the unblocked answers at the bottom of the page.
Second, do you have a subform on that form that's using the autonumber/key field on the master form? Do you require the data that's on that subform to be saved (i.e., having its own key) before the main form is saved. You could be into a deadlock of A and B requiring each other to be saved first.
Other than that, you must somehow be accessing that autonumber field whenyou are saving it. The best I can suggest is to step through the code line by line.
Are you trying to assign the value of an Identity field to a variable or something else before you have saved the record?
For whatever reason, your app is trying to read the value of the identity field before the record has been saved, which is what generates that identity field. In other words, no value exists for the Autonumber field until the row is saved.
I think we'd need to see more code or know more about the steps that lead up to this error to resolve it in more detail.
You should have add some lines of code to show us how you're managing your data and what you are doing exactly. But I am suspecting an issue related to a recordset update. can you identify when the autonumber value is created? Is it available in a control on a form? Can you add a control to display this value to check how it is generated when adding a new record? Is the underlying recordset properly updated? Can you add something like me.recordset.update on some form events: I would try the OnCurrent one ...